Frame saw



March 16, 1937. E. LGF 2,073,898

FRAME SAW Filed 001:. 9,, 1935 2 Sheets-Shez et lv 6 Fi .1.

March 16, 1937. I

FRAME SAW Filed 001;. 9, 1955 2 Sheets-Sheet 2 Patented Mar. 16, 1937 UNITED STATES FRAME SAW Emil Liif, Stockholm, Sweden Application October 9, 1935, Serial No. 44,281 In Sweden October 10, 1934 1 Claim.

This invention relates to vertical frame saws and more specifically to improved means for lifting the upper feeding rollers of the saw.

It is known to provide frame saws with mechanically operated lifting means for the upper feeding rollers to facilitate the introduction of the work piece to be out between the feeding rollers of the saw. The starting and stopping of such lifting means were hitherto carried out by hand by the operator which caused a loss of time and reduced the efficiency of the saw.

The object of this invention is to remove said drawback by carrying out the lifting means in such manner that the starting and stopping of said means are performed by the log supplied to the saw and thus is performed without requiring any attendance of the operator. I use for such purpose swingable dogs or the like placed in the path of the work piece in advance of each of the upper feeding rollers, said dogs being actuated upon by the work piece when the latis saved and a more perfect cutting of the work piece can be attained. Said dogs are combined with and form operating means for starting mechanically operated devices by means of which first the upper feeding roller on the front side of the saw and then the upper feeding roller on the back side are lifted to such extent that the work piece supplied to the saw can be introduced between the feeding rollers. The said dogs are, preferably, journalled in such manner that they partake in the vertical movements of the rollers, the lower ends of the dogs being situated somewhat higher than the lowermost part of the roller whereby it is attained that the dog is disengaged from the work piece when the corresponding roller has been raised sufficiently to allow the introduction of the work piece below the roller. By means of a spring, acounterweight, or the like the dog is then returned to its normal position whereby the lifting means is switched off.

In the accompanying drawing I have shown an embodiment of the improved frame saw. Fig. 1 shows a front view and Fig. 2 a side view of 50 the saw.

Referring to the drawing, I, I are the upper feeding rollers of the frame saw. The lifting means for each of said rollers consists of a cylinder 2 secured to the frame 3 and containing a piston 4 which by means of a piston rod 5, a cross-piece 6 and rods 1 is connected to the supporting frame 8 of the upper roller. A tube 9 connects the cylinder 2 with a three-way cook it to which is also connected a tube II for the supply of a liquid or gaseous pressure fluid, said cock being by means of links l2 connected with a lever l4 journalled on a pin [3 in the roller frame 8. The lever l4 forms a dog which is 10 actuated upon by the work piece when the latter is supplied to the frame saw I thus causing the cock 10 to be turned to supply the pressure fluid to the cylinder 2 whereby the piston 4 is moved and raises the upper feeding roller sufficiently 15 to allow the introduction of the work piece below said roller. As the lever 14 is journalled on the I frame of the upper feeding roller it accompanies the roller in the upward movement and when the latter has been lifted sufficiently for the introducing of the work piece below said roller the lever I4 is disengaged from the work piece and falls back to its normal position, causing the cock in to be reversed so that the supply of the pressure fluid to the cylinder 2 is cut off 25 and the latter is opened to the atmosphere. On account thereof the roller I can fall down on the work piece with its full weight; The same operation is repeated when the work piece is pushed in between the feeding rollers on the back side 30 of the frame saw.

The invention is not limited to the use ofllydraulic or pneumatic cylinders for the lifting of the upper feeding rollers but may also be used in connection with other well-known or suitable 35 means for such purpose, as for instance in connection with mechanical lifting devices having power transmission from the crank shaft of the saw by a coupling which is operated by a dog actuated upon by the work piece. 40

What I claim is:--

A frame saw, comprising pressure rollers, vertically movable frames supporting said rollers, means for lifting said frames and rollers, trip levers journalled on said frames so as to normally project into'the path of the Work and connected to said lifting means to start the latter when acted upon by a work piece, and means to return the trip levers into inoperative position when the supporting frames have been lifted sufliciently to allow the work to enter below the pressure rollers.

EMIL L61. 

